Why do people love each other? It's all about healthier children.
A comparative survey of couples suggests that the bond of true love is forged in the genes. People are more attracted to those who have very different immunity genes from their own. The genes in question play a major role in the immune system's ability to fight infections, but they also leave a lingering trace in the scent of people's body odour. Humans sniff out partners who have different immunity genes because they tend to produce healthier children with stronger immune systems.
So, love is not about feelings. People who can produce healthier children are forced to love each other by their genes.